Scientific Reports (Jun 2021)

Detection of SARS-CoV-2 RNA in serum is associated with increased mortality risk in hospitalized COVID-19 patients

  • Diego A. Rodríguez-Serrano,
  • Emilia Roy-Vallejo,
  • Nelly D. Zurita Cruz,
  • Alexandra Martín Ramírez,
  • Sebastián C. Rodríguez-García,
  • Nuria Arevalillo-Fernández,
  • José María Galván-Román,
  • Leticia Fontán García-Rodrigo,
  • Lorena Vega-Piris,
  • Marta Chicot Llano,
  • David Arribas Méndez,
  • Begoña González de Marcos,
  • Julia Hernando Santos,
  • Ana Sánchez Azofra,
  • Elena Ávalos Pérez-Urria,
  • Pablo Rodriguez-Cortes,
  • Laura Esparcia,
  • Ana Marcos-Jimenez,
  • Santiago Sánchez-Alonso,
  • Irene Llorente,
  • Joan Soriano,
  • Carmen Suárez Fernández,
  • Rosario García-Vicuña,
  • Julio Ancochea,
  • Jesús Sanz,
  • Cecilia Muñoz-Calleja,
  • Rafael de la Cámara,
  • Alfonso Canabal Berlanga,
  • Isidoro González-Álvaro,
  • Laura Cardeñoso,
  • the REINMUN-COVID Group

DOI
https://doi.org/10.1038/s41598-021-92497-1
Journal volume & issue
Vol. 11, no. 1
pp. 1 – 11

Abstract

Read online

Abstract COVID-19 has overloaded national health services worldwide. Thus, early identification of patients at risk of poor outcomes is critical. Our objective was to analyse SARS-CoV-2 RNA detection in serum as a severity biomarker in COVID-19. Retrospective observational study including 193 patients admitted for COVID-19. Detection of SARS-CoV-2 RNA in serum (viremia) was performed with samples collected at 48–72 h of admission by two techniques from Roche and Thermo Fischer Scientific (TFS). Main outcome variables were mortality and need for ICU admission during hospitalization for COVID-19. Viremia was detected in 50–60% of patients depending on technique. The correlation of Ct in serum between both techniques was good (intraclass correlation coefficient: 0.612; p < 0.001). Patients with viremia were older (p = 0.006), had poorer baseline oxygenation (PaO2/FiO2; p < 0.001), more severe lymphopenia (p < 0.001) and higher LDH (p < 0.001), IL-6 (p = 0.021), C-reactive protein (CRP; p = 0.022) and procalcitonin (p = 0.002) serum levels. We defined "relevant viremia" when detection Ct was < 34 with Roche and < 31 for TFS. These thresholds had 95% sensitivity and 35% specificity. Relevant viremia predicted death during hospitalization (OR 9.2 [3.8–22.6] for Roche, OR 10.3 [3.6–29.3] for TFS; p < 0.001). Cox regression models, adjusted by age, sex and Charlson index, identified increased LDH serum levels and relevant viremia (HR = 9.87 [4.13–23.57] for TFS viremia and HR = 7.09 [3.3–14.82] for Roche viremia) as the best markers to predict mortality. Viremia assessment at admission is the most useful biomarker for predicting mortality in COVID-19 patients. Viremia is highly reproducible with two different techniques (TFS and Roche), has a good consistency with other severity biomarkers for COVID-19 and better predictive accuracy.